The Aurora proteins are a family of three related serine/threonine kinases (termed Aurora-A, -B and -C) that are essential for progression through the mitotic phase of cell cycle. Specifically Aurora-A plays a crucial role in centrosome maturation and segregation, formation of the mitotic spindle and faithful segregation of chromosomes. Aurora-B is a chromosomal passenger protein that plays a central role in regulating the alignment of chromosomes on the meta-phase plate, the spindle assembly checkpoint and for the correct completion of cytokinesis.
Overexpression of Aurora-A, -B or -C has been observed in a range of human cancers including colorectal, ovarian, gastric and invasive duct adenocarcinomas.
A number of studies have now demonstrated that depletion or inhibition of Aurora-A or -B in human cancer cell lines by siRNA, dominant negative antibodies or neutralizing antibodies disrupts progression through mitosis with accumulation of cells with 4N DNA, and in some cases this is followed by endoreduplication and cell death.
The Aurora kinases are attractive targets due to their association with numerous human cancers and the roles they play in the proliferation of these cancer cells. It would be desirable to have an Aurora kinase inhibitor with favorable drug-like properties, such as stability in human liver microsomes. Accordingly, there is a need for compounds that inhibit Aurora kinases and also exhibit favorable drug-like properties.